Thursday, 9 May 2013

magnification & real size


Unit 1 quiz & answers

Unit 1 AS biology quiz  Answers - Miss Timms


1.      What kind of bond links amino acids together? Peptide bond.
2.      What type of reaction is involved in linking amino acids together? Condensation reaction
3.      What four different components make up an amino acid? Amino group, carboxyl group, r group and hydrogen atom.
4.      What is a catalyst? Catalysts alter the rate of a chemical reaction without undergoing permanent changes.
5.      Why are enzymes effective in tiny quantities? They can be reused repeatedly and are therefore effective in small quantities.
6.      Explain why enzymes function less well at lower temperatures? A reduction in temperature leads to a reduction in kinetic energy of the molecules within the reaction, so less collision occur and the reaction is slower.
7.      Why is the electron microscope able to resolve objects better than the light microscope? As the electron beam has a shorter wavelength than light.
8.      In which process are ribosomes important? Protein synthesis
9.      What is the overall function of the cell-surface membrane? It forms a boundary between the cell cytoplasm and the environment, allowing different condition to be established inside the cell compared to outside.
10.  What is the name of the blood vessel that supplies the heart muscle with oxygenated blood? Coronary arteries.
11.  List the correct sequence of the four main blood vessels and four heart chambers that a red blood cell passes through on its journey from the lungs, through the heart and body, and back again to the lungs? Pulmonary vein, left atria, left ventricle, aorta, superior and inferior vena cava, right atria, right ventricle and pulmonary artery.
12.  Indicate whether each of the following statements are true or false?
a.       The left and right ventricles contract together? True
b.      Heart muscle is myogenic? False (only in SAN and AVN)
c.       Semi-lunar valves occur between the atria and ventricles? False
d.      The wave of electrical activity from the atrioventricular node is conveyed along the bundle of His? True
e.       The wave of electrical activity from the sinoatrial node directly causes the ventricles to contract? False
13.  What is an antigen? Any part of an organism or substance that is recognised as non-self (foreign) by the immune system and stimulates an immune response.
14.  State two differences between T cells and B cells?
B cells
T cells
·         Matures in bone marrow
·         Matures in thymus gland
·         Involved in humoral immunity
·         Involved in cell-mediated immunity
·         Responds to foreign material outside body cells
·         Responds to foreign material inside body cells
·         Responds to bacteria and viruses
·         Responds to own cells altered by viruses or cancer and to transplanted tissues
15.  Explain how high temperatures (above 60 degrees) may completely prevent enzymes from functioning? Denaturation (protein unfolding and aggregation) may occur which is the permanent change of an enzyme no longer allowing it to function.
16.   Why do specimens have to be kept in a near-vacuum in order to be viewed effectively using an electron microscope? Because electrons are absorbed by the molecules in air.
17.  Name the organelle that is being referred to in each of the following descriptions?
a.       It possesses structures called cristae? Mitochondria.
b.      It contains chromatin? Nucleus.
c.       It synthesises glycoproteins? Golgi apparatus.
d.      It digests worn out organnells? Lysosomes.

Thursday, 2 May 2013

Unit 2 Quiz – The variety of living organisms- Answers

1.      State three ways in genetic variation can be increased in sexually reproducing organisms? Mutations, meiosis, fusion of gametes

2.      How is genetic variation increased in asexually reproducing organisms? Only by mutation

3.      Give definitions for interspecific variation and intraspecific variation? Interspecific – species differ from one another, intraspecific – members of the same species differ

4.      Give two reasons why a sample may not be representative of the populations as a whole? Sampling bias and chance

5.      How may sampling bias be prevented? Random sampling (divide study area into a grid, random number generator and intersection of coordinates)

6.      Draw and label a nucleotide? Phosphate, deoxyribose and organic base


7.      In terms of the structure of the DNA molecule explain why the base pairings are not A with G and T with C? C/T are single ring bases and G/A are double ring bases. The base pairs are always made up of one of each

8.      If the base pairs on one strand of DNA are TGGAGACT what is the base sequence on the other strand? ACCTCTGA


9.      If 19.9% in human DNA are G what percentage of human DNA is T? 30.1%

10.  What is a gene? A section of DNA that contains the coded information for polypeptides.


11.  How many bases of DNA are required for a chain of 6 amino acids? (triplet code) 18 bp

12.  What is the function of the protein found in chromosomes? DNA is wound around protein molecules to keep it in place (histones)


13.  In which two ways does meiosis lead to an increase to a genetic diversity? Recombination by crossing over, independent segregation of chromosomes

14.  Describe the quaternary structure of haemoglobin? Four polypeptides, two alpha, two beta – each with a Haem group containing a ferrous ion.


15.  Why is the process of DNA replication described as semi conservative? Half of the original DNA is saved and built into the new DNA molecules (P165)

16.  What are the three main stages of the cell cycle? Cell division, interphase, nuclear division (mitosis)


17.  What is a tissue? Collection of similar cells that perform a specific function

18.  Name three factors which affect the rate of diffusion of a substance into cells? (Ficks law) SA, conc gradient, diffusion distance


19.  What is meant by counter current flow and why is it an efficient means for transporting gases across fish gills?  Blood and water travel in opposite directions, constant rate of diffusion across length of gill, 80% O2 abs into blood – parallel 50%

20.  Distinguish between horizontal and vertical gene transmission? Horizontal – DNA can be passed from one species to another, vertical – genes passed down from one generation to the next within the same species.

Thursday, 25 April 2013

stuff on kerboodle to do for revision

any of the questions can be printed and completed for us to go through in the lesson- bring them in and I will check them through with you.

LUNGS:Breathing animation
Lungs – chapter 4 exam style questions
Lungs extension questions

HEART:
Cardiac cycle animation
Analysis of the cardiac cycle- extension revision
Heart and heart disease quiz
Heart- chapter 5 exam style questions
The question pack from the lesson

IMMUNITY:
Humoral response animation
Maths skills- antibodies in the blood
HSW vaccines & society
Immunity quiz
Chapter 6 immunity exam style questions

UNIT 1 exam style questions- i suggest you all have a go at these

Tuesday, 23 April 2013

Thursday, 18 April 2013

group presentations/ quizzes/ activities for unit 1

We will do these presentations/ quizzes/ activities will be done on tuesday 30th April

Email me any work you need to print/ photocopy

·      Disease- Henry, Ellie & Ben
·      Digestion
·      Cells- sarah, Jordan & lucy
·      The heart- martha maddie
·      The lungs- nanki & abi
·      Immunology- Ahsan, Mawada & Maisha

If anyone wants to do one on digestion let me know

Disease independent work


1.Disease podcast
2.Disease- test yourself
3.Disease exam-style questions
4.Maths skills- counting bacteria using standard form
5.Maths skills- scatter diagrams
6.Bacteria & virus animation
7.HSW revision activity (heart disease)
8.Disease exam questions from the lesson
 
Bring me any work that you complete

revision schedule

Week 1- disease
Week 2- cells (+effect of human activity on biodiversity presentations)- unit 2 progress retake
Week 3- the heart & lungs
Week 4- digestion & immunology

Tuesday, 26 March 2013

Friday, 22 March 2013

Biodiversity work

Apologies for not being in the lesson yesterday, I have been really ill and didn't want to pass on my horrible virus!

I have put loads of work to do on kerboodle- summarising the classification topic, a podcast about biodiversity and some other activities to work through. I have also put spares of the exam-style qs on there in case you lose them. There are some test-yourself questions on kerboodle aswell.

It should tell you which activities to print out to return to me and which ones I will mark electronically. If you download the resources and complete them electronically you can email them to me to save you printing them (rti@cheney.oxon.sch.uk)

On tuesday we will be practising calculations of species diversity index- a common exam q in unit 2.
bring a calculator as I dont have that many spare.

Remember thursday to bring your homework for peer-assessment and to prepare for revision lessons.

thanks
Ms Timms

Tuesday, 12 March 2013

Charles Darwin

http://darwin-online.org.uk/Introduction.html

Research the work of Charles Darwin

- Natural selection
-history of Darwin
-survival of the fittest

Darwin's works:
On the origin of species
Expression of emotion in man & animals

Thursday, 28 February 2013

homework 28th feb


1.Make a glossary of new terminology from this lesson.
2.Produce model answers for the exam questions on the blog.
3.Watch wonders of life
4.Read notes on the blog and elaborate with your own notes.

Thursday, 21 February 2013

images for gas exchange in plants






DNA trip

I am writing to tell you about the exciting opportunity we have been given to take a group of students to the Oxford University Museum of Natural History for a DNA workshop. This event takes place on Friday 1st March 2013, 9.30-3.00 pm.  

Students will use PCR to investigate human evolution. It will involve them analysing and comparing their version of a bitter taste receptor gene to their ability to taste. Students will learn about molecular biology techniques by using research-quality equipment. The workshop will be relevant for all Year 12 Biologists as it complements several areas of the course.

We will meet outside Oxford University Museum of Natural History at 9.15am on the Friday; students will have to make their own way to and from the Museum for this visit and will be registered on site. Students will need to bring a packed lunch and a drink as there are no lunch facilities at the museum.

Homework-21st feb


1.Watch the ‘wonders of life’ episode- size matters
(great information about how the size of organisms is linked to their surface area to volume ratio)
2. Revise structure of plant cells and leaves for next Thursday
3. Revise DNA structure for workshop on Friday! Hand in your slip if you haven't already so you have a reserve place.